It is desirable to enhance the strength of articles molded from thermoplastic resins, such as polybutylene terephthalate. Usually a reinforcing material such as glass fiber, asbestos fiber or other fibrous material may be employed in the resin to increase strength. In addition, fillers such as glass beads, platelets, or particulate minerals may be used to aid in increasing modulus.
Even though reinforcing and filling materials enhance the strength of articles molded from the resin, it is desirable to obtain even stronger articles, and particularly desirable to obtain articles having good resistance to breakage on sudden impact.